The structure of existing foam pumps belongs to piston pump, with gas piston and liquid piston coaxial arranged in the bottle cover, the common products in the market are assembled by adding a guide pipe and a spray head, which are of difficult structure.
Some Chinese patents have made improvements about the foam pump aimed at its deficiencies, however, the structure is still difficult, most of them require 10-12 accessories for assembly, some small parts require precise mould, and gas piston is still arranged in the bottle cover, so it still requires bottleneck and bottle cover with large diameter to obtain enough gas amount.
Such as a foam pump in the market, the piston outside diameter of the gas piston pump is 31 mm, and the diameter of bottom outer cover is 46.6 mm. The actual effective travel is 15 mm, the total height of two overlapped piston pumps, mixed pipe and spray head is 125 mm. The foam pump of this structure cannot be arranged in common 32 mm bottleneck of 3 mL lotion bottle.
Chinese patent CN202624901 discloses a foam pump, it uses O-ring as an air cylinder piston and arranges the air cylinder piston on the bottle cover, so small bottle cover can be used to fit piston with 31 mm diameter, the bottle cover outer diameter of common bath pump is 34 mm. However, the foam pump does not have balancing hole, so that the foam pump cannot be used continually due to negative pressure in the bottle, besides, it is not so clear that how to enter air when the air cylinder breath in. More to the point, this foam pump is of difficult structure, there are 17 accessories in total, a cover, a seal ring and a guide pipe are excluded.
And such as a foam comb, two pressure tanks are adopted to start hair dye and form foam, which is of high cost and not environmental protection; and the process is to pour oxidant lotion into squeeze bottle for mixed squeeze, generate foam and coat on comb, which is inconvenient to use.